NH 66
Panvel–Kanyakumari Highway
Also known as National Highway 17 (old numbering), Includes the Kochi–Kanyakumari stretch of the former NH 47 and West Coast Highway
1,640 km
Open
5 states
National Highway
Route
NH 66 runs 1,640 km from Panvel, Maharashtra to Kanyakumari, Tamil Nadu.
Crosses Maharashtra, Goa, Karnataka, Kerala and Tamil Nadu.
Through Panvel, Ratnagiri, Panaji, Karwar, Udupi, Mangaluru, Kannur, Kozhikode, Kochi, Alappuzha, Kollam and Thiruvananthapuram.
Why it matters
NH 66 is the west coast's main street. It carries fish, coconuts, cashew, rubber and spices out of the coastal belt, brings millions of tourists to Goa and Kerala, and is the everyday road to school, market and hospital for the towns squeezed between the Western Ghats and the sea. Because the mountains block most east–west roads, for long stretches there simply is no other route.
History
NH 66 hugs India's western coast from Panvel, just outside Mumbai, all the way to Kanyakumari at the country's southern tip. For most of its life it was known as NH 17, a winding two-lane road through the Konkan, Goa, coastal Karnataka and Kerala; the 2010 renumbering joined it with part of the old NH 47 to reach Kanyakumari. The old road was famous for being slow and dangerous — narrow, full of blind curves, and squeezed between the Western Ghats and the sea, so a 600 km drive from Mumbai to Goa could swallow a whole day. Since the late 2010s it has been rebuilt in pieces: the Konkan stretch got a tunnel through the Kashedi ghat, Goa got two big cable-stayed bridges, and Kerala took on one of its largest ever building projects to turn its share into a six-lane road. Work has been slow and much delayed by heavy monsoons, land purchase disputes and the sheer number of rivers to cross, so in 2026 the highway is still a mix of brand-new six-lane sections and old two-lane bottlenecks.
Good to know
- Runs about 1,640 km along the Arabian Sea coast through five states.
- Crosses dozens of rivers, estuaries and backwaters between the Western Ghats and the sea.
- Runs roughly parallel to the Konkan Railway for much of its length.
- Passes through Panaji, the capital of Goa.
- The Kerala section is being rebuilt as a wide six-lane highway, one of the state's biggest infrastructure projects.
- It is the main street of the Konkan coast — for hundreds of villages between Mumbai and Mangaluru it is the only proper road.
- The Kashedi ghat twin tunnels turned a 45-minute crawl over a hill into a roughly 10-minute drive.
- It shares its southern end at Kanyakumari with NH 44, India's longest highway.
Timeline
- 2010Renumbered as NH 66, replacing the old NH 17 and part of the old NH 47
- 2025Large sections of the rebuilt, wider highway in Kerala open to traffic in phases
Key junctions
- Panvel, Maharashtra — the northern start, where NH 66 leaves NH 48 on the edge of the Mumbai region
- Panaji, Goa — crosses the Mandovi river on the Atal Setu beside the state capital
- Mangaluru, Karnataka — meets the highway climbing east to Bengaluru through the Shiradi ghat
- Kochi (Edappally), Kerala — busy city junction with the highway heading inland to Thrissur, Palakkad and Coimbatore
- Kanyakumari, Tamil Nadu — the southern end, shared with NH 44
Engineering highlights
- Kashedi Ghat twin tunnels — about 1.7 km of twin three-lane tubes under a steep Konkan hill; opened in stages 2023–24 and cut a 45-minute climb to roughly 10 minutes
- Atal Setu, Goa — cable-stayed bridge over the Mandovi river at Panaji, opened 2019 — a different bridge from the Mumbai one with the same name
- New Zuari Bridge, Goa — cable-stayed bridge over the Zuari river; the first carriageway opened in December 2022 and the second in December 2023
- Thalapady–Chengala six-lane section — about 39 km in Kasaragod district, opened in 2025 — the first of the Kerala six-laning stretches to be finished
On the road
Mumbai to Goa is roughly 600 km and takes about 10–12 hours, longer where old two-lane sections survive. It is one of India's prettiest drives — palms, rivers, ferry crossings and sudden sea views — but the monsoon from June to September brings very heavy rain, landslides on the ghat sections and poor visibility, so October to February is the easy season. Traffic peaks around Diwali, Christmas and New Year when Goa fills up; roadside stalls sell Malvani and Konkani seafood in Maharashtra and Goa, and small tea shops line the Kerala stretch.
What’s coming next
- Kerala's share of NH 66 is being rebuilt as a six-lane highway in more than twenty separate stretches, opening in phases.
- The remaining narrow parts of the Mumbai–Goa section in Maharashtra are being widened to four lanes.
More details
- Lanes
- Varies from 2 to 6 lanes; major widening under way